A woman fries potatoes this Wednesday at her home in Seville.PACO PUENTES / EL PAÍS
Frying carries the prejudice that it is a cooking technique that makes you fat. However, the researcher at the Fat Institute of the Higher Council for Scientific Research (IG-CSIC) María Victoria Ruiz Méndez recalls that there are already studies that show that frying is not only a popular way of cooking but also “efficient”. A new work on the effects of different oils in the frying of food has confirmed that, in addition to improving the appearance and palativity (quality of a food product of being pleasant to the palate), it increases the compounds of nutritional interest due to its hypotensive effects, antidiabetic, anti-inflammatory and in the inhibition of cholesterol absorption. Of all the vegetable oils studied, that of pomace (extracted from the second pressing of the olive), is the one that has demonstrated the best physical and chemical behavior
The incorporation of vegetable fat into food is produced by its absorption by part of the food during preparation. "The greater the surface area and porosity, the greater it will be," says Ruiz Méndez. In this way, as he explains, a breaded or battered product will absorb more, as will 100 grams of thin potatoes than the same amount cut into larger wedges. But this effect is compensated by the nutritional contribution generated by the oil and, especially, the olive pomace, which has shown not only greater resistance in the frying process but also less alteration compared to that of high oleic sunflower, high oleic sunflower. with antifoam and seed oil. "Due to the dilution effect, the content of saturated fatty acids and the cholesterol level are decreased while the content of phytosterols [compounds whose consumption reduces the absorption of lipoproteins in the intestine]", explains the researcher.
The frying with pomace exerts a protective action of the minority nutritional elements and maintains the bioactive compounds without altering the flavor of the food thanks to its neutral sensory characteristics
The new study completes another by Gloria Márquez Ruiz , Scientific researcher at the Institute of Science and Technology of Food and Nutrition (ICTAN-CSIC), who has already detected a better behavior of pomace oil both in discontinuous frying (that carried out in domestic kitchens and restoration) as well as in the industrial sector, in addition to exerting a protective action of minority nutritional elements and maintaining bioactive compounds without altering the taste of food thanks to its neutral sensory characteristics.
Ruiz Méndez's research has analyzed how and in to what degree these bioactive and antioxidant compounds are maintained when the oil is subjected to high temperatures to be ingested with fried food. The test has shown that frying dissolves cholesterol in food and reduces its absorption thanks to the action of phytosterols (natural sterols of plant origin). According to the European Food Agency (EFSA ), consuming between 1.5 and three grams a day of these compounds for three weeks can reduce low-density lipoproteins (LDL), known as bad cholesterol, in 11% .
The permanence of tocopherols, related to vitamin E and with antioxidant effects, has also been proven. “The encapsulation of the food that is produced when frying it makes the interior is protected and its properties are more conserved”, explains Ruiz Méndez.
Frying with olive pomace oil increases the compounds of nutritional interest due to its hypotensive, antidiabetic, anti-inflammatory effects and in the inhibition of cholesterol absorption.
The study also shows that, among the nutritional compounds that frying retains, there are some that are maintained in a special way when using the fat of the olive pomace, such as squalene, a natural organic compound, also present in the liver oil of shark, rice bran and wheat germ, which are attributed beneficial effects on eye and skin health as well as cancer and cardiovascular disease prevention
To a greater extent, frying with pomace preserves other components such as phytosterols (70%), the triterpenic alcohols erythrodiol and uvaol (80%) and the triterpenic acids (60%) or provides aliphatic alcohols, absent in the food if it is not fried. These contribute to an increase in good cholesterol (between 8% and 15%) and a reduction in bad cholesterol (up to 30%).
José Luis Maestro Sánchez-Cano, president of Oriva, the interprofessional organization of pomace oil, supports the results of the work, which has promoted: “ We believe in research because there is a gap on the healthy and culinary properties of olive pomace oil ”. In this sense, Oriva has promoted six investigations by the CSIC, which is completing another two studies this year. One of the next challenges is in the field of pastry.
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